Method of simultaneously transmitting and receiving space-telegraph signals.



m. 7|6,|s7f Patented Dec. I6, I902.

.J. s. sums.

METHOD OF SIMULTANEOUSLY TRANSNMTTING AND RECEIVING SPACE TELEGRAPH SIGNALS.

(Application filed Jan. 23, 1901. Renewed Feb. 24, 1902.)

(No Model.)

UNITED STATES PATENT OF ICE.

JOHN STONE STONE, OF BOSTON, MASSACl-IUSETTS,-ASSIGNOR TO LOUIS E. WHIOHER, ALEXANDER P. BROWNE, AND BRAINERD T. JUDKINS,

TRUSTEES.

METHOD OF SIMULTANEOUSLY TRANSMITTING AND RECEIVING SPACE- TELEGRAPH SIGN ALS.

SPECIFICATION forming-part of Letters Patent No. 716,187, dated December 16, 1902. Application ille'd January 23, 190 1. Renewed February 24, 1902. Serial No. 96,199. (in model.)

1'0 (tZZ- whom it may cmtcerrt:

Be it'known that I, JOHN STONE STONE, a citizen of the United States, residing at Boston,- in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Methods of SimultaneouslyTransmittingand Receiving Space- Telegraph Signals, of which the following is a specification.

The invention relatesto the art of signaling electrically between stations not connected by a conducting-wire, sometimes called space telegraphy, and more particularly to the system of space telegraphy in which the signals are transmitted by means of unguided electromagnetic waves emanating from elerated conductors. For convenience this'lat- .ter system shall hereinafter be designated as the elevated-conductor system of space telegraphy to distinguish it. from other systems ofsignaling electrically between stations not connected by a conducting-wire.-

. If in the elevated conductor system of space telegraphy as at present-practiced a receiving-station be placed in the immediate neighborhood of a transmitting-station, the receiviugapparatus of the receiver-station is affected by signals from the transmittingstation. 'lhe result of this fact is that a receiving-station placed in theim mediate neighborhood of a transmitter-station is rendered useless while the transmitting-station is sendmg signals, and a message from 'a remote transmitting-station will not beintelligently received at the receiviug station while a inessage is being transmitted from the neighboringtransmittingrstation..

The object of the present invention is to supply a method whereby a receiver and a transmitter station placed in close proximity to'one another may be operated simultaneously, the transmitter-station sending signals to a distant receiverestation and the receiver-station receiving intelligible signals from a distant transmitting-station without interferenceby the signals sent out from the neighboring transmitting-station.

The phenomenon upon' which the present invention depends for its operationis one which is the electrical analogue of. the pheuomenon of interference in sound and light.

opposite in phase Iprefer to place them half vtors have developed in them electric oscillation equalin amplitude and opposite in phase, electromagnetic waves will emanate 'from each, and at all points equally distant from the two vertical conductors these waves will be equal and opposite. Such points lie ina vertical plane equidistant between the two vertical conductors, and since the electromagnetic waves frolnthe two vertical conductors are throughout this plane equal and opposite theirelfect throughout this plane is m'Z. 'We maythereforeplace in this vertical 6 plane, which we shall call the plane of interference, vertical receiving -conductors which will be nnafiected by the oscillations developed in the two transmitting-conductors. v7 Careful consideration will show that more than two vertically-elevated transmittingconductors maybe used,provided -the amplitudes and phases of their oscillations be properly chosen, with the result that planes or 7 lines of interference are developed, and several vertically-elevated IGCBlVBlsCOIldllCtOI'S may be placed in these planes crimes of 'interferencer The receiver conductors will tnenbe unaifected by the oscillation in the 8 t'ransmit'ting-conductors. D

I prefer to so place the transmitting-conductors that the resulting electromagnetic waves are most powerful in the direction of the receiving-station with which it is desired to communicate. For example, if two verti cal transmitter conductors are employed 'whose oscillations are equal in amplitude and a complete .wave length apart and in a verti- 9 cal plane including the vertical conductor of the distant receiver-station with which it is desired to communicate, so that waves emanating from the two vertical conductors of the transmitting-stations shall reinforce each other in this particular direction.

When it'is desired to communicate with receiver-stations in ditTerent directions from the transmitter-station, I mount the receiver and transmitter-conductors upon a rigid frame capable of being rotated about a vertical axis and rotate the frame until the plane of the transmitter-conductors includes the vertical conductor of the particular receiver-station with which it is desired to communicate.

If two vertical transmitter-conductors are employed in which the oscillations developed are equal both in amplitude and phase and if they be placed at a coinplete'wavelength apart, then also will there be vertical planes of interferencehalf-way between them, in which may be erected vertical receiver-conduct-ors which will be unaffected by the oscillations in the transmitter-conductors.

The figure illustrates an embodiment of the invention.

In the figure, V V V are vertical wires. G is the ground. M, M, M, and M are 'induction-coils. O is a condenser, E is a battery, R isa relay, K is a coherer, and a is a generator of vibratory currents. The generator a is shown diagrammatically and is intended to represent any generator of vibratory-currents suitable for use in an elevatedconductor system of wireless telegraphy, the preferable form being that ineach by the use of a spark-coil an oscillatory discharge of a condenser is obtained-such generators, for instance, as have been employed in highfrequency experiments. notably by Nikola Tesla and Elihu Thomson. If in this organization it be determined to employ in V and V electric vibrations equal both in amplitude and phase, the wires V and V are placed acomplete wave length or a multiple of a complete wave length apart; but if it be determined to employ in V and V electric vibrations equal in amplitude and opposite in phase then the wires V and V are placed half a wave length apart or an odd multiple of half a wave length apart. The question as to whether the phases of the vibrations in V and V will be the same or opposite is determined by the direction of the windings of the coils M and M in the usual way.

In the operation of this organization the generator adevelop's electric vibrations,which are communicated through the intermediary of the coil M to the coils M and Mand thence to the vertical wires V and V. The oscillations thereby produced in the wires V and V develop electromagnetic waves which interfere in a'vertical plane half-way between the vertical conductors; but they agree in phase to the right and leftflof the system, and therefore 'reinforce'each other in these directions. The vertical receiving-wire V is placed in the plane of interference and is therefore unaffected by the waves developed by V and V, whereas it receives the energy of Waves from other transmitter-stations at a distance.

As regards the operation of the receiving apparatus associated with the elevated conductor V electromagnetic signal-waves emanoting from a distant transmitter-station and impinging upon this conductor develop therein electric vibrations which through the intermediary of the transformer-coil M are conveyed to the coherer K, which is thereby operated. The operation of the coherer permits the battery'B to develop a current in the circuit D M K R of sufficient force to set in motion the relay R. The coherer K is acted upon by a decoherer, (not shown in the drawing,) which restores it to its normal condition of high resistance after the passage of each signal,

Having fully described my invention, I claim-- 1. The method of transmitting electromagnetic signal-waves and of simultaneously receiving other electromagnetic signal-waves, which consists in generatingthe electromagnetic signal-waves to be transmitted by producing electric vibrations in two or more vertical conductors and in receiving the energy of signal-waves to be received in vertical conductors placed in lines or planes of interference of the signal-waves to be transmitted.

2. The method of simultaneously transmitting and receiving electromagnetic signalwaves, which consists in generating ata transmitting-station a plurality of sets of electromagnetic signal-waves, neutralizing the effect of said waves in a receiving-conductor at said station, and absorbing the energy of simultaneously-transmitted waves from a distant station by said receiving-conductor.

b. The method of simultaneously transmitting and receiving electromagnetic signalwaves, which consists-in generating two sets of electromagnetic signal-waves at a transmitting-station and neutralizing the effects of 1 said sets of waves on a receiving-conductor, situated in a certain definite relation to the transmitting means, whereby a receiver associated withlsaid receiving-conductor is maintained in a sensitive condition with respect to waves simultaneously transmitted from other stations. I

4. The method of transmitting electromagnetic signal-waves which consists in simultaneously impressing on two grounded elevated conductors, situated at a distance apart which bears a certain definite relation to the length of the wave to be transmitted, electric vibrations of a certain predetermined phase relation. I

5. The method of transmitting electromag netic signal-waves which consists in si nulta' neously impressing on two grounded elevated conductors situated a distance apart equal to one-half the length of the waves to be transmitted, electric vibrations of opposite phase.

6. The method of reinforcing the effective radiation of electromagnetic signal-waves in the plane of two grounded elevated transmitti ng-conductors,which consists in placing said conductors a distance apart which bears a certain definite relation to the wave to be transmitted, and simultaneously impressing electric vibrations on said conductors.

JOIIN STONE S'IONE. In presence of- ALEX. P. BRoWNE, ELLEN B. TOMLINSON. 

